Shock mount for collapsible antennae



April 29, 1947. WALSH 2,419,611.

SHOCK MOUNT FOR GOLLAPSIBLE ANTENNAS Filed April so, 1943 X7Z-7V0ED W! fig I Z X 5 1 J 70 RAD/0 m m/aw) IN ENTOR ALLEN A ALSH. PFTEACTEQ, BY

J v I ATTORNEY Patented Apr. 29,1947

SHOCK MOUNT FOR COLLAPSIBLE ANTENNAE Allen A. Walsh, West Englewood, N. J assignor to Radio Corporation of America, a corporation of Delaware Application April 30, 1943, Serial No. 485,122

This invention relates to a new and useful shock absorbing antenna mount.

An object of this invention is to provide a simple and eificient flexible mount for an antenna which is particularly adapted for absorbing mechanical shocks and the prevention of mechanical injury.

Another object of this invention is to provide an improved telescoping antenna structure which is made up of component parts, some of which are capable of being employed as additional or series loading inductance in the antenna.

A feature of this invention is the arrangement of a mounting plate coupled together with an antennasleeve by means of a coil spring, the antenna member being arranged to be extended or retracted through the sleeve spring and mounting plate. The antenna mount of this invention makes possible the use of a telescoping antenna with a resilient spring mount arranged to prevent mechanical iniury to the extended portion of the antenna. The antenna mount of this invention is particularly useful with portable radio apparatus, such as transmitters and receivers wherein it is desirable to have a built-in antenna made of telescoping sections so that it may be adjusted to any desired length and when not in use collapsed into the main assembly. Antennae of this type, as known in the prior art, are usually constructed in several sections of thin wall metal tubing which are often damaged beyond repair by merely striking some object sufficiently hard to bend a tube section.

This application is a further improvement in antennae of the type shown by a Hathaway Paterlt 2,161,707 dated June 6, 1939.

This invention will best be understood by referring to the accompanying drawing in which:

Fig. 1 is an elevation of the antenna mounting of this invention,

Fig. 2 is a plan view of Fig. 1,

Fig. 3 is a diagram showing the antenna member connected to form a series loading inductance, and

Fig. 4 is a sectional detail showing a modification of Fig. 1.

Referring now to Figs. 1 and 2 of the drawing, the fundamental portion of the antenna 1 comprises two or more pieces of thin wall metal tubes IA, IB and IC which are arranged to telescope within each other. A base plate 2 is provided with suitable apertures 3 for mounting the antenna to the desired apparatus which ma be that of a radio receiving or transmitting set. There is also provided a lower coil support 1 which is secured by suitable means, such as threading or a 5 Claims. (Cl. 250-33) sliding fit to the mounting plate 2. An antenna sleeve 4 is located slightly above the base plate 2 and is secured thereto by means of an inductive helical coil spring 5 of metal, and is fastened to members 1 and 4 by any suitable means such as, for example, by welding or soldering. With the antenna I extended the bottom section fits tightly into the swaged tube 6 to make good electrical connection, also so that any mechanical shock is transmitted to the coil spring which will absorb the shock and thus prevent damage to the extended sections. When the antenna is not in use, it may be collapsed as shown in a retracted position as indicated by the dash and dot lines. The top end of tube IA is terminated with a small metallic ball 9.

As shown by Figs. 3 and 4 the coil spring 5 may be used as a series loading inductance by selecting the number of turns and the diameter of the helix to obtain the required amount of series inductance. When the antenna is used in this manner, the electrical connection is made between the antenna assembly portion above member I and the appaartus at the mounting plate 2. If it is desired to use the spring mount without the additional'series inductance, the antenna sleeve I4 should be made of a non-conducting material such as, for example, Bakelite or Isolantite. Other portions of the antenna are insulated to obtain the desired electrical circuit characteristics. Electrical connection is then made by a single flexible conductor 15 connected to the swaged tube 6 and the apparatus and also through the inside of the coil spring 5.

While I have indicated and described a system for carrying my invention into eifect, it will be apparent to one skilled in the art that my invention is by no means limited to the particular mechanism shown and described, but that many modifications may be made without departing from the scope of my invention.

What I claim is:

l. A collapsible antenna mount comprising a metallic tube serving as the antenna member, a base mounting plate having a plurality of apertures therein for securing it to radio apparatus, an antenna sleeve member, a spring support member secured to said mounting plate, a helical spring wound with open spaced turns and electrically fastened to said antenna sleeve and said spring support member to serve as a series loading inductive coil for said antenna circuit, and means within said mounting plate and sleeve member for permitting the passage of said antenna member.

2. A collapsible antenna member 'having in combination a metallic tube, a swaged tube secured to an end of said metallic tube, a sleeve member surrounding said swaged tube and a portion of said metallic tube, an inductive coil spring member secured to said sleeve member, a coil support, an antenna, base mounting plate coupled to said coil support, said inductive coil spring member being electrically connected in series between said coil support and said swaged tube to make electrical connection to said metallic tube by having said coil serve as a series loading inductance for said antenna.

3. A collapsible antenna member including a plurality of telescoping metallic tubes, a sleeve member for supporting said telescoping metallic tubes, a helical spring member acting as an inductive coil, a coil support member, a base mounting plate for retaining said coil support member, said helical spring member being electrically connected in series between said support member-and said antenna member to serve as a series loading inductance for said antenna.

4, A collapsible antenna comprising a plurality of telescoping tubes serving as the antenna, a base mounting plate having a central aperture therein for the passage of said telescoping tubes therethrough when in the collapsed position, an antenna sleeve surrounding the outermost of said telescoping metallic tubes, a metallic spring support member threaded to be secured to said base mounting plate, a helical spring wound with open spaced turns electrically fastened to said antenna sleeve and one end of said spring support member, whereby the helical spring serves as a series loading inductive coil for said antenna and also serves to absorb mechanical shocks for the prevention of mechanical injury thereof.

5. A collapsible antenna comprising a plurality of telescoping tubes serving as the anntenna, a base mounting plate having a central aperture therein for the passage of said telescoping tubes therethrough when in the collapsed position, an antenna sleeve surrounding, the outermost of said telescoping metallic tubes, a metallic spring support member threaded to be electrically secured to said base mounting plate, a helical spring Wound With open spaced turns electrically fastened to said antenna sleeve and one end of said spring support member arranged to serve as series loading inductance in the antenna circuit and to permit removal of said helical spring for selecting other springs having a different number of turns and a different diameter to obtain another required amount of series inductance for said antenna circuit.

ALLEN A. WALSH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,144,038 Trump Jan. 17, 1939 2,098,388 l-Iruska Nov. 9, 1937 2,161,707 Hathaway June 6, 1939 2,207,692 McPherson July 9, 1940 2,180,107 Hathaway Nov. 14, 1939 2,206,820 Mydlil July 2, 1940 

